1. Field of the Invention
The present invention relates to a disc apparatus that performs recording to or reproduction from a disc such as a CD or a DVD, and more particularly to a structure for assembly of a tray into such a disc apparatus.
2. Description of Related Art
In conventionally known disc apparatuses, a disc is placed on a tray, which is then moved into the apparatus cabinet, and the disc is then clamped between a disc holder (that is, a clamper) and a turntable, of which both are provided inside the apparatus cabinet. This makes the disc ready for recording or reproduction. In recent years, a variety of proposals have been made for better workability in assembly and other work on such disc apparatuses.
For example, JP-A-2004-310804 discloses a disc loading apparatus that can be assembled into an apparatus base by being slid in the transport direction of transporting means and that in addition permits proper adjustment of the meshing position between a gear mechanism including a partially toothless gear and a rack of the transporting means mesh.
Specifically, the disc loading apparatus disclosed in JP-A-2004-310804 is provided with: a tray base for transporting a disc; a drive mechanism for driving the tray base; a rack that is provided on the tray base and that meshes with an output gear of the drive mechanism; a drive gear train that includes the output gear and a partially toothless gear and that forms part of the driving mechanism; a slit wall portion that is provided on the top-face side of the drive gear train and whose orientation coincides with the movement direction of the tray base when the partially toothless gear is in a predetermined rotation position; and a protruding portion that is provided integrally with the tray base and that, as the tray base moves, passes through a slit passage that runs in the above-mentioned orientation.
On the other hand, JP-A-2002-288916 discloses a disc apparatus that prevents the mesh between a rack of a tray and a drive gear from being released during assembly of the tray. Specifically, in the disc apparatus disclosed in JP-A-2002-288916, a clearance portion is provided between teeth of the drive gear, and a large-width portion having a width corresponding to the clearance portion is provided in a guide-in portion of the rack of the tray. Here, during assembly of the tray, the large-width portion of the tray fits in the clearance of the drive gear, in which state the meshing position between a first gear and the rack of the tray coincides with the meshing position between a second gear and a movable base drive portion. This ensures that assembly of the tray is completed in a single step of work.
Disadvantageously, however, with a structure like that of the disc loading apparatus disclosed in JP-A-2004-310804, there is little freedom when the slit wall portion is brought into the orientation coincident with the movement direction of the tray base when the partially toothless gear is in a predetermined rotation position, and moreover a complicated mechanism is needed. On the other hand, with a structure like that of the disc apparatus disclosed in JP-A-2002-288916, it is impossible to cope with cases where a drive gear needs to be brought into a particular meshing position. Conventionally, in a case where a drive gear needs to be brought into a particular meshing position as just mentioned, it is customary to perform assembly of a tray while restricting the orientation of a tray-drive gear with a jig or the like. This is inconvenient and impairs workability.